1. Field of Invention
The present invention relates to a front end water box with an automatic on-line rubber ball cleaning function in a condenser, which is particularly applicable to a tubular condenser of a 2-pass water cooled chiller, and at the same time applicable to a 2-pass tubular flooded evaporator thereof as well as a 2-pass water cooled tubular heat exchanger with cooling water through tube pass at a temperature not exceeding 80° C.
2. Related Art
Existing automatic on-line rubber ball cleaning devices in a condenser of a water cooled chiller are categorized into the following two types. One type is an independent cleaning system device, which is connected to the inlet and outlet of the condenser through pipelines. A ball sending device sends rubber balls into the inlet pipeline of cooling water. The rubber balls flow into the condenser with the cooling water, flow out of the outlet of cooling water after cleaning, flow into a ball capturing device, and then enter the ball sending device again. Such a cleaning device has the following defects: 1. the cleaning device needs on-site installation and construction, which requires a high work load, so that the cleaning device is unable to be delivered with the chiller; 2. as it is required to send balls at a high speed, great dynamic power is configured for sending the balls, for example, a water pump, an air compressor, or a water flow with a large pressure difference is needed. The other type is to set four-way flow reversing devices at the inlet and outlet of the condenser, and cleaning elements are installed inside the heat exchange tube of the condenser. Inner walls of the heat exchange tubes are cleaned through the reciprocating movement of the cleaning elements as the flow direction changes. Referring to Chinese Patent Publication No. CN101451297A, such an automatic cleaning device through flow direction changes has the following two defects: 1. during the direction change, high temperature water enters the condenser, instantaneously a great change occurs to the condensing temperature of refrigerant inside the condenser of a chiller, and instantaneous efficiency of the chiller is greatly fluctuated, posing great impact to the operation of the chiller and even causing side effects such as surges in the chiller; 2, as the water flow speed in each heat exchange tube is different due to distribution of the water flow field on the tube plate of the condenser, after operation for a period of time, some cleaning elements are stuck in blocking elements and cannot make reciprocating cleaning movement.